<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			.aaa{
				width: 100px;
				height: 100px;
				background: red;
				border-radius:100px 0 0 0; 
			}
		</style>
	</head>
	<body>
		<div class="aaa" onclick="aaa()"></div>
	</body>
</html>
<script type="text/javascript">
	function aaa(){
		console.log('a')
	}
	function bbb(){
		console.log('b')
	}
</script>